Columna litológica del Sondeo El Cubo (Tegueste)litoestratigrafía del sector noroccidental del Edificio Antiguo de Anaga (Tenerife, Islas Canarias)

Resumo

The “El Cubo” borehole is located in the western part of the Old Basaltic Edifice of Anaga, near Pedro Alvarez village (Tegueste). It was in order to investigate the hydrogeological features of the area and its possibilities as a water supply source to the Municipality. The lithologic section of this borehole is basically composed of basanite-tephrite laves, that are more abundant at the bottom of the sequence, phonotephrites and basaltic trachyandesites that are more frequent at the top of the sequence, and basaltic pyroclastic fall layers that are more abundant in the middle and upper parts of the section. The sequence represents the evolvement from ultrabasic terms towards the bottom to basic and intermediate terms towards the upper part, defining an intermediate igneous series between an alkaline series (alkaline olivine basalt (Nef=0-5%) – trachyte) and a strongly alkaline series (basanite (Nef>5%, Alb>5%) – phonolite). Chronological dating demonstrate that the 580 m sequence is limited between 4.3 and 4 Ma, indicating a very fast growth rate for this part of the Anaga Edifice, in only 400.000 years.,.